1. Field of the Invention
The present invention relates to urology, in particular, to a method and apparatus for treating patients with benign prostatic hyperplasia.
2. Description of Prior Art Technique
At the present time, laser technologies find wide application in medicine for surgery. In particular, in the field of urology, a conventional cystoscope is commonly used to perform laser operations in the urethra, bladder, and prostate (see Urology Johnson, D. E., Laser Prostatectomy Using Right-Angle Delivery System. Lasers in Urology. Laparascopy and General Surgery, Vol. 1421, p. 36, 1991). A laser fiber is inserted into the axial channel of the cystoscope, while a liquid which is used for filling the urinary bladder is supplied through the sheath.
In the course of such an operation, for example, a laser prostatectomy, the filling and irrigation liquid is periodically removed from the system. For this purpose, the operation is discontinued, a valve is opened, all or a part of the existing liquid is drained from the bladder and replaced with fresh liquid. The operation is then resumed. Poor heat-removal conditions which arise in the operation area during operation with the use of the above-described conventional cystoscope sometimes lead to the overheating of the metal laser tip to such an extent that it has to be replaced before the operation may proceed.
Very often during the operation the laser tip comes into contact with tissue in the prostate affected area. This causes the prostate tissue to adhere to the reflecting surface of the laser-beam emitting device. As a result, the operation has to be discontinued, and the laser fiber has to be removed for cleaning purposes. This is an extremely inconvenient and time-consuming operation.
Furthermore, the radially inwardly directed forces developed by the enlarged prostate constrict the prostatic part of the urethra, whereby the field of vision is obscured.